12-Bar Blues Song Form

It is important to not confuse the song structure, 12-bar blues, with the genre of music known as the blues. The 12-bar blues song form is used in many genres of music including country, jazz, rock, folk, and, yes, blues.

It is a simple song form that is based on a 3-chord progression. These three chords, relative to the key of the song, are known as:

I (one)
IV (four)
V (five)

The capital Roman numerals represent major chords. So in the key of C Major, the chords would be C (the one), F (the four), and G (the five). To try to make this more clear, think of D as “the two” and E as “the three.” There will be more lessons in chord progressions, but for now, let’s just play with the I, IV, V of the key of C Major: C, F, and G.


…and then repeat, returning back to the C (the I chord)

The numbers in the top row represent the bars of music, let’s say 4 beats each in a 4/4 rhythm (so that the 12 bars altogether have 48 beats), and the the letters in the bottom row represent the chords to play.

Notice the G7 has the 7 added to it. This is what is called a “dominant 7.” It’s “dominant” because when you hear it in this context, your ear really, really, really wants to hear the C chord after it.

There are dozens of variations of this 12-bar blues form. Some of these variations might only start off with two measures of the I chord before jumping to the IV chord. This is known as a “quick two.” In jazz, some of these I, IV, V chords are replaced with similar sounding chords but which might add a colorful note or two to the chord. So instead of playing

IV – V7 – I (i.e. F – G7 – C)

a jazz musician might play

ii7 – V7 – I (i.e. D minor7 – G7 – C).

You have probably heard the 12-bar blues song form many, many times during the course of your whole life. It is easy to follow and is a very simple and powerful way to get your message across, thus it’s popularity.

Song Spark Workbook

Sign Up For Our Newsletter and Receive the Song Spark Workbook for Free!

You'll also get tips on songwriting, how to deepen your faith, and important notices about the contest.

Your subscription could not be saved. Please try again.
Success! Please check your inbox (and spam folder) to confrim your subscription.

Subscribe to the Catholic Song Contest newsletter and stay updated.


Get in touch, we will be happy to help!